Podolsky D K
Gastrointestinal Unit, Harvard Medical School, Boston 02114, USA.
J Gastroenterol. 1997 Feb;32(1):122-6. doi: 10.1007/BF01213309.
The gastrointestinal epithelium produces a wide variety of peptides which may contribute to protection from injury as well as repair after injury occurs. Restitution, the initial phase of mucosal repair, is accomplished by rapid migration of the epithelium to re-establish surface epithelial continuity. A wide variety of growth factors and cytokines, which are produced both by the epithelium itself and by lamina propria cell populations, promote restitution in models of epithelial injury. These include members of the epidermal growth factor (EGF)/transforming growth factor (TGF)alpha, and the fibroblast growth factor (FGF) families, as well as a variety of cytokines (interleukin [IL]-1, IL-2, IL-4, IL-15, and interferon gamma) which interact with their cognate receptors on the intestinal epithelial basolateral surface. These growth factors and cytokines appear to promote restitution through a TGF beta-dependent pathway and act to both enhance expression of TGF beta and to entrance its bioactivation. In contrast, trefoil peptides, members of a recently recognized family of small proteins produced by goblet cells, both protect the epithelium and promote restitution following secretion onto the apical surface through mechanisms distinct from those peptides acting through TGF beta. Thus, rapid repair after epithelial injury is achieved through complementary mechanisms acting at the basolateral and apical surfaces of the epithelium.
胃肠道上皮会产生多种肽类物质，这些肽类可能有助于预防损伤以及在损伤发生后进行修复。黏膜修复的初始阶段即再生，是通过上皮细胞的快速迁移来重新建立表面上皮连续性而实现的。上皮自身以及固有层细胞群体产生的多种生长因子和细胞因子，在上皮损伤模型中促进再生。这些因子包括表皮生长因子（EGF）/转化生长因子（TGF）α家族成员、成纤维细胞生长因子（FGF）家族成员，以及多种细胞因子（白细胞介素[IL]-1、IL-2、IL-4、IL-15和干扰素γ），它们与肠上皮基底外侧表面的同源受体相互作用。这些生长因子和细胞因子似乎通过一条依赖TGFβ的途径促进再生，作用于增强TGFβ的表达并使其生物激活。相比之下，三叶肽是杯状细胞产生的一个最近才被认识的小蛋白家族的成员，它既能保护上皮，又能通过与那些通过TGFβ起作用的肽不同的机制，在分泌到顶端表面后促进再生。因此，上皮损伤后的快速修复是通过在上皮基底外侧和顶端表面起作用的互补机制实现的。
